A 0.32pJ/b 90Gbps PAM4 Optical Receiver Front-End with Automatic Gain Control in 12nm CMOS FinFET

This work presents a 0.32pJ/b90Gbps PAM4 optical receiver (RX) front-end with a 13.4pA/$\sqrt{}$Hz noise density. The proposed design employs a new transimpedance amplifier (TIA) and a single-ended-to-differential (S2D) block providing a large gain-bandwidth product with less power and area overhead compared to the conventional designs. The proposed RX is implemented in 12nm CMOS FinFET process and co-packaged with a commercial photodiode (PD), offering the best power efficiency, input-referred noise, and figure-of-merit (FOM) amongst the previous state-of-the-art designs [1] –[5].